The corn leafhopper Dalbulus maidis (Hemiptera: Cicadellidae), a specialist herbivore, is the cause of serious losses in maize yield for its capacity to transmit three important plant pathogens. They are also active phloem feeders, that insert stylets into the plant as they feed. Females place their eggs endophytically, totally inserted in the central midrib or the leaf blades, leaving conspicuous openings in the place where the ovipositor was inserted. In spite of the consequences that feeding and oviposition may have on the water status of the plant and the production of biomass, direct damage caused by the leafhopper has been only scarcely studied. In the present contribution, we measured biomass loss due to direct damage in maize plants under two watering regimes, with water supply ad libitum and with a watering restricted regime, emulating the most frequent field conditions. Moreover, we analyzed the effects of increasing densities of the vector on the biomass loss and plant mortality and the effects of females vs males. We observed that a density of 10 insects is sufficient to cause damage to 10-day-old seedlings, even in an ad libitum watering regime; however, in drought conditions, damage can be significantly greater, causing plant mortality. Also, females cause more damage than males, due to their oviposition habits.

中文翻译：

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不同浇水条件下玉米叶蝉Dalbulus maidis（半翅目：蝉科）对玉米幼苗直接损害的估计

玉米叶蝉雏菊（半翅目：蝉科）是一种专门的食草动物，由于其传播三种重要植物病原体的能力，导致玉米产量严重下降。它们也是活跃的韧皮部喂食器，在喂食时将管心针插入植物中。雌性将它们的卵内生放置，完全插入中央中脉或叶片中，在插入产卵器的地方留下明显的开口。尽管摄食和产卵可能对植物的水分状况和生物量的产生产生影响，但几乎没有研究过叶蝉造成的直接损害。在目前的贡献中，我们测量了两种浇水方式下玉米植物直接损害导致的生物量损失，供水随意并采用浇水限制制度，模拟最常见的田间条件。此外，我们分析了增加载体密度对生物量损失和植物死亡率的影响以及雌性与雄性的影响。我们观察到 10 只昆虫的密度足以对 10 天大的幼苗造成损害，即使在随意浇水制度；然而，在干旱条件下，损害可能会更大，导致植物死亡。此外，由于产卵习惯，雌性比雄性造成的伤害更大。